System and method for assembly manufacturing

ABSTRACT

A method for assembly manufacturing including positioning a workpiece in an assembly position within an operational cell, positioning a fastening machine relative to the workpiece, wherein the fastening machine includes a robot frame comprising a throat, an assembly end effector coupled to the frame about the throat, and a plurality of linear actuators coupled to the frame, moving, by the plurality of linear actuators, the fastening machine about at least one of six degrees of freedom to receive at least a portion of the workpiece within the throat and position the assembly end effector relative to the workpiece, and performing, by the fastening machine, a fastening operation on the workpiece.

PRIORITY

This application is a divisional of U.S. Ser. No. 15/244,194 filed onAug. 23, 2016, which is a divisional of U.S. Ser. No. 14/222,878 filedon Mar. 24, 2014.

FIELD

The present disclosure is generally related to assembly manufacturingand, more particularly, to a system and method for assemblymanufacturing of a large structural workpiece.

BACKGROUND

A number of manufacturing applications exist in which large structuralworkpieces are assembled and, in many cases, joined to form a finalstructure. For example, large monument machine tools and tooling may beused for assembling large workpieces, such as large panels used forassembling wing planks, wing panels or wing assemblies of aircraft.However, traditional systems have been barriers to attaining a moreefficient manufacturing process.

For example, current manufacturing processes for large, structuralworkpieces feature large, floor-mounted machine tools and expensivetooling. The size of the assembly machines is a result of requirementsfor throat depth and the multiple custom axes for reaching all surfacesof the workpiece. These monument machines and tooling utilize excessivefloor space and cannot be reconfigured between different types ofstructural workpieces. Furthermore, moving large workpieces, forexample, by crane may be time-consuming and may create a bottleneck inthe manufacturing process. Such delays may leave machine tools idledduring material handling and set-up. Additionally, the traditionalmanufacturing is highly dependent on manual processes, such as fasteningworkpieces during the assembly process.

Accordingly, those skilled in the art continue with research anddevelopment efforts in the field of assembly manufacturing.

SUMMARY

In one embodiment, the disclosed method for assembly manufacturing mayinclude the steps of: (1) positioning, by a material-handling system, anunassembled workpiece in a first assembly position within a tackingcell, (2) performing, by a first plurality of fastening machines, a tackfastening operation on the unassembled workpiece to form a partiallyassembled workpiece, (3) transferring, by the material-handling system,the partially assembled workpiece from the tacking cell to a fasteningcell, (4) positioning, by the material-handling system, the partiallyassembled workpiece in a second assembly position within the fasteningcell, and (5) performing, by a second plurality of fastening machines, afinal fastening operation on the partially assembled workpiece to forman assembled workpiece.

In another embodiment, the disclosed method for assembly manufacturingmay include the steps of: (1) positioning a workpiece in an assemblyposition within an operational cell, (2) positioning a fastening machinerelative to the workpiece, wherein the fastening machine may include arobot frame including a throat, an assembly end effector coupled to theframe about the throat, and a plurality of linear actuators coupled tothe frame, (3) moving, by the plurality of linear actuators, thefastening machine about at least one of six degrees of freedom toreceive at least a portion of the workpiece within the throat andposition the assembly end effector relative to the workpiece, and (4)performing, by the fastening machine, a fastening operation on theworkpiece.

Other embodiments of the disclosed system and method for assemblymanufacturing will become apparent from the following detaileddescription, the accompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of one embodiment of the disclosed system forassembly manufacturing;

FIG. 2 is a block diagram of another embodiment of the disclosed system;

FIG. 3 is a block diagram of another embodiment of the disclosed system;

FIG. 4 is a block diagram of another embodiment of the disclosed system;

FIG. 5 is a block diagram of another embodiment of the disclosed system;

FIG. 6 is a schematic illustration of one embodiment of thematerial-handling system of the disclosed system;

FIG. 7 is a schematic illustration of one embodiment of the roboticassembly of the disclosed system;

FIGS. 8A, 8B, 8C and 8D are schematic illustration depicting theoperational positions of the material handling system;

FIG. 9 is a schematic illustration of one embodiment of the fasteningmachine of the disclosed system;

FIG. 10 is a schematic illustration of one embodiment of one operationcell of the disclosed system;

FIG. 11 is a schematic illustration of another embodiment of theoperation cell;

FIG. 12 is flow diagram of one embodiment of the disclosed method forassembly manufacturing;

FIG. 13 is flow diagram of an aircraft production and servicemethodology; and

FIG. 14 is a block diagram of an aircraft.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings,which illustrate specific embodiments of the disclosure. Otherembodiments having different structures and operations do not departfrom the scope of the present disclosure. Like reference numerals mayrefer to the same element or component in the different drawings.

Referring to FIG. 1, one embodiment of the disclosed system, generallydesignated 10, for assembly manufacturing may include a plurality offunctional operation cells 12. In one example of an assembly manufactureoperation, the plurality of operation cells 12 may assembly a workpiecein an unassembled condition 14 (referred to generally as unassembledworkpiece 14) into a workpiece in an assembled condition 16 (referred togenerally as an assembled workpiece 16).

In one embodiment, the plurality of operation cells 12 may include atleast one staging cell 18, at least one tacking cell 20, at least onefastening cell 22 and at least one extraction cell 24. The plurality ofoperation cells 12, in combination, may acquire the unassembledworkpiece 14, perform one or more assembly operations to assemble theunassembled workpiece 14 into the assembled workpiece 16 and yield theassembled workpiece 16. In one example implementation, the plurality ofoperation cells 12 may be utilized for assembly manufacture oflarge-scale structural panels, such as those typical to a commercialaircraft including, but not limited to, wing skin planks, wing skinpanels, fuselage body side panels or wing assemblies.

In a specific, non-limiting aerospace example, the unassembled workpiece14 may include a plurality of stringers and at least one skin sectionand the assembled workpiece 16 may include a wing plank. For example,the plurality of stringers and at least one skin section (e.g., theunassembled workpiece 14) may be transported to the staging cell 18. Theplurality of stringers and at least one skin section may be positionedat an appropriate initial fastening position within the tacking cell 20.For example, the skin section may be positioned in a generallyhorizontal position and each stringer of the plurality of stringers maybe positioned in a fastening position on the skin section. The tackingcell 20 may perform one or more machining and/or assembly operations onthe plurality of stringers and the skin section to initially fasten theplurality of stringers to the skin section. A partially assembledplurality of stringers and skin section may be positioned at anappropriate final fastening position within the fastening cell 22. Thefastening cell 22 may perform one or more machining and/or assemblyoperations on the plurality of stringers and the skin section to finallyfasten the plurality of stringers to the skin section. For example, thepartially assembled plurality of stringers and skin section may bepositioned in a generally horizontal position and each stringer of theplurality of stringers may be finally fastened to the skin section. Afully assembled plurality of stringers and skin section may then bepositioned within the extraction cell 24 for removal of the fullyassembled plurality of stringers and skin section (e.g., the assembledworkpiece 16).

In another specific, non-limiting aerospace example, the unassembledworkpiece 14 may include at least two wing planks and at least onesplice stringer and/or at least one side of body and the assembledworkpiece 16 may include a wing assembly. For example, the at least twowing planks and at least one splice stringer and/or at least one side ofbody (e.g., unassembled workpiece 14) may be transported to the stagingcell 18. The at least two wing planks may be positioned at anappropriate initial fastening position within the tacking cell 20. Forexample, the wing planks may be positioned in a generally horizontalposition and at least one splice stringer and/or at least one side ofbody may be positioned in a fastening position on the wing planks (e.g.,between edge interfaces of the wing planks). The tacking cell 20 mayperform one or more machining and/or assembly operations on the at leasttwo wing planks and at least one splice stringer and/or at least oneside of body to initially fasten the splice stringer and/or side of bodyto the wing planks. A partially assembled wing planks, splice stringerand/or side of body may be positioned at an appropriate final fasteningposition within the fastening cell 22. The fastening cell 22 may performone or more machining and/or assembly operations on the partiallyassembled wing planks, splice stringer and/or side of body may tofinally fasten the splice stringer and/or side of body to the wingplanks. For example, the partially assembled wing planks, splicestringer and/or side of body may be positioned in a generally horizontalposition and the splice stringer and/or side of body may be finallyfastened to the wing planks. A fully assembled partially assembled wingplanks, splice stringer and/or side of body may then be positionedwithin the extraction cell 24 for removal of the fully assembledpartially assembled wing planks, splice stringer and/or side of body(e.g., the assembled workpiece 16).

Referring to FIG. 2, in another embodiment, the plurality of operationcells 12 may be linked together by a common material-handling system 26.In another example of an assembly manufacture operation, amaterial-transport system 28 may be loaded with the unassembledworkpiece 14 and deliver the unassembled materials to the staging cell18. The material-handling system 26 may remove the unassembled workpiece14 from the material-transport system 28 and position the unassembledworkpiece 14 in the tacking cell 20. The tacking cell 20 may perform atleast one assembly operation on the unassembled workpiece 14 to form apartially assembled workpiece 30. The material-handling system 26 mayremove the partially assembled workpiece 30 from the tacking cell 20 andposition the partially assembled workpiece 30 in the fastening cell 22.The fastening cell 22 may perform at least one assembly operation on thepartially assembled workpiece 30 to form the assembled workpiece 16. Thematerial-handling system 26 may remove the assembled workpiece 16 fromthe fastening cell 22 and move the assembled workpiece 16 to theextraction cell 24 where the assembled workpiece 16 may be positioned onthe material-transport system 28 for transport to another location.

Referring to FIG. 3, in another embodiment, a plurality of operationcells 12′ may be linked to the plurality of operation cells 12. Theassembled workpiece 16 may become unassembled workpiece 14′, which aredelivered (e.g., via the material-transport system 28) to the pluralityof operation cells 12′. The plurality of operation cells 12′ may includeat least one staging cell 18′, at least one tacking cell 20′, at leastone fastening cell 22′ and at least one extraction cell 24′. Theplurality of operation cells 12′ may be linked together by a commonmaterial-handling system 26′. The plurality of operation cells 12′ mayperform one or more assembly operations on the unassembled workpiece 14′to assemble an assembled workpiece 16′. Those skilled in the art willrecognize that additional pluralities of operation cells may be linkedas many times as necessary to assembly manufacture a final assembledworkpiece.

Referring to FIG. 4, in another embodiment, the plurality of operationcells 12 may include at least one staging cell 18, at least one tackingcell 20, at least one fastening cell 22, at least one tacking cell 20′,at least one fastening cell 22′ and at least one extraction cell 24. Theplurality of operation cells 12 may be linked together by a commonmaterial-handling system 26. The plurality of operation cells 12 mayperform one or more assembly operations on the unassembled workpiece 14to assemble an assembled workpiece 16. Those skilled in the art willrecognize that additional tacking cells and/or additional fasteningcells may be included in the plurality of operation cells 12 asnecessary to assembly manufacture a final assembled workpiece.

As will be described in more detail herein, in yet another embodiment(not shown), the staging cell 18 and/or the extraction cell 24 may beeliminated from the plurality of operation cells 12, depending upon themanner in which the unassembled workpiece 14 are loaded into the tackingcell 20 and/or how the assembled workpiece 16 is unloaded from thefastening cell 22.

Referring to FIGS. 5 and 6, in an example embodiment, the plurality ofoperation cells 12 (e.g., at least one staging cell 18, at least onetacking cell 20, at least one fastening cell 22 and/or at least oneextraction cell 24) may be arranged in a linear configuration (e.g., anassembly line). The material-handling system 26 may include a pair oftransfer rails 32 (only a single transfer rail 32 is shown in FIG. 6).The transfer rails 32 may extend substantially the entire length of theplurality of operation cells 12. For example, the transfer rails 32 mayextend longitudinally from the first cell (e.g., the staging cell 18 inFIG. 6) to the last cell (e.g., the extraction cell 24 in FIG. 6) of theplurality of operation cells 12. The transfer rails 32 may be positionedabove (e.g., overhead transfer rails) the plurality of operation cells12. For example, the transfer rails 32 may be positioned above afunctional operation area 34 (e.g., the area where one or more assemblyoperations is performed) of each of the plurality of operation cells 12.

In an example construction, the transfer rails 32 may be supported in asubstantially horizontal position by a plurality of substantiallyvertical support stanchions 46. In another example construction, thetransfer rails 32 may be connected to and extend between opposingstructures, such as walls or structural support beams of a manufacturingfacility.

In an example construction, at least one gantry 36 (a plurality ofgantries 36 are shown in FIG. 6) may be operably connected between thepair of transfer rails 32. The transfer rails 32 may be spaced apartlaterally, for example, to the outside of the plurality of operationcells 12 (FIG. 7). Each gantry 36 may include at least one roboticassembly 38. The gantry 36 may be linearly movable along the pair oftransfer rails 32, for example, in the direction of arrow 52. The gantry36 may longitudinally traverse the pair of transfer rails 32 to positionthe robotic assembly 38 over any one of the plurality of operation cells12 (e.g., within the functional operation area 34 of each of theplurality of operation cells 12). For example, the gantry 36 (or theplurality of gantries 36) may traverse the pair of transfer rails 32from proximate a first end 48 to proximate a second end 50.

The gantry 36 may be driven upon the pair of transfer rails 32 by anysuitable driving system (not shown) including, but not limited to, amechanical driving system, an electromechanical driving system, ahydraulic driving system, a pneumatic driving system or the like. In aspecific, non-limiting example, the gantry 36 may be driven by and/orthe relative position of the gantry 36 with respect to each of theplurality of cells 12 may be controlled by one or more servomechanisms.

Referring to FIG. 7, the robotic assembly 38 may include a robotcarriage 40 operably connected to an underside of the gantry 36 (e.g.,above the functional operation area 34). A robotic arm 42 may beoperably connected to the robot carriage 40. The robot carriage 40 maybe linearly movable along the gantry 36, for example, in the directionof arrow 54. The robot carriage 40 may traverse a substantial length ofthe gantry 36 (e.g., between laterally opposed transfer rails 32) toposition the robotic arm 42 at any one of a plurality of predeterminedpositions within the functional operation area 34 of each of theplurality of operation cells 12 (e.g., the staging cell 18, the tackingcell 20, the fastening cell 22 and/or the extraction cell 24). Forexample, the robot carriage 40 may traverse the gantry 36 from proximatea first end 55 to proximate a second end 56.

The robot carriage 40 may be driven upon the gantry 36 by any suitabledriving system (not shown) including, but not limited to, a mechanicaldriving system, an electromechanical driving system, a hydraulic drivingsystem, a pneumatic driving system or the like. In a specific,non-limiting example, the robot carriage 40 may be driven by and/or therelative position of the robot carriage 40 with respect to each of theplurality of cells 12 may be controlled by one or more servomechanisms.

The robot carriage 40 and the robotic arm 42 may include any roboticassembly suitable for assembly manufacturing operations. In a specific,non-limiting example, the robot carriage 40 and/or the robotic arm 42may be an industrial robot platform, such as commercially available fromKUKA Robotics Corporation of Gersthofen, Germany

An end effector 44 may be disposed at an end of the robotic arm 42. Therobotic arm 42 may include one or more independently articulating armsegments to position the end effector 44 at any one of a plurality ofpredetermined positions within the functional operation area 34 of eachof the plurality of operation cells 12. The robotic arm 42 may beconfigured to move and/or position the end effector 44 at any location,for example, in the direction of arrow 58 (e.g., along the X-axis),arrow 60 (e.g., along the Y-axis) and/or arrow 62 (e.g., along theZ-axis). The robotic arm 42 may be configured to rotate and/or positionthe end effector 44 at any location, for example, in the direction ofarrow 64 (e.g., about the X-axis), arrow 66 (e.g., about the Y-axis)and/or arrow 68 (e.g., about the Z-axis). In a specific, non-limitingexample, the robotic arm 42 and/or the end effector 44 may be driven byand/or the relative position of the robotic arm 42 and/or end effector44 with respect to each of the plurality of cells 12 may be controlledby one or more servomechanisms.

Thus, the robotic arm 42 may provide the end effector 44 with of freedomof movement along six axes (e.g., along the X-, Y- and/or Z-axis andabout the X-, Y- and/or Z-axis) and the robot carriage 40 may providefreedom of movement (e.g., linear movement) along a seventh axis (e.g.,along the X-axis).

The end effector 44 of each robotic arm 42 may be customized to grip,handle, carry and/or manipulate the unassembled workpiece 14. Forexample, the end effector 44 may include any suitable mechanism 70configured to grip or clamp a specific type of unassembled material 14(e.g., individual pieces of the unassembled workpiece 14). In followingwith the aerospace example above, one or more end effectors 44 of one ormore robotic assemblies 38 may be configured to grip a skin section, astringer, a wing plank, a splice stringer and/or a side of bodycomponent.

In another example construction, the material-handling system 26 mayinclude a monorail system or similar overhead handling system (notshown). For example, the transfer rails 32 (FIG. 5) may be configured asa cantilever system (not shown), for example, extending from a wall or asupport beam. The cantilever system may include a plurality ofcantilever beams (not shown) positioned above each operation cell 12 ofthe plurality of operation cells 12 (e.g., the staging cell 18, thetacking cell 20, the fastening cell 22 and/or the extraction cell 24).One or more robotic assemblies 38 (FIG. 5) may be operably connected toan underside of each cantilever beam of the cantilever system (e.g.,above the functional operation area 34). The robotic assembly 38 may belinearly movable along the cantilever beam, for example, by the robotcarriage 40. For example, the robot carriage 40 may traverse asubstantial length of the cantilever beam to position the robotic arm 42of the robotic assembly 38 at any one of a plurality of predeterminedpositions within the functional operation area 34 of a respectiveoperation cell 12 (e.g., the staging cell 18, the tacking cell 20, thefastening cell 22 and/or the extraction cell 24).

Referring to FIGS. 8A, 8B, 8C and 8D, in an example assemblymanufacturing operation, the material-handling system 26 may engage,transfer and/or position the unassembled workpiece 14, the partiallyassembled workpiece 30 (FIG. 2) and/or the assembled workpiece 16 (FIG.2) from and between the plurality of operation cells 12. In an exampleimplementation, the material-handling system 26 may utilize repeatablemachine positioning and machine accuracy to engage and place theworkpiece (e.g., the unassembled workpiece 14, the partially assembledworkpiece 30 and/or the assembled workpiece 16) at appropriatepositioned between and within the plurality of operation cells 12. Inanother example implementation, the material-handling system 26 mayutilize one or more metrology systems 124 (e.g., laser tracking, laserradar, Intelligent Global Pooling Systems (iGPS), RFID tracking and thelike) to provide for appropriate positioning of the workpiece betweenand within the plurality of operation cells 12.

For example, the gantries 36 may initially be positioned in a firstposition (e.g., positioning the robotic assemblies 38 within thefunctional operational area 34 of the staging cell 18), as illustratedin FIG. 8A. The unassembled workpiece 14 (FIG. 6) may be positionedwithin the functional operation area 34 of the staging cell 18, forexample, by the material-transport system 28 (FIG. 6). The roboticassemblies 38 may engage (e.g., grip and lift) a first component of theunassembled workpiece 14 while in the first position. The gantry 36 maymove to a second position (e.g., positioning the robotic assemblies 38within the function work area 34 of the tacking cell 20), as illustratedin FIG. 8B. The robotic assemblies 38 may transfer the first componentof the unassembled material 14 to an assembly position within thetacking cell 20.

The gantries 36 may return to the first position and the roboticassemblies 38 may engage a second component of the unassembled material14 while in the first position. The gantries 36 may move to the secondposition and the robotic assemblies 38 may transfer the second componentof the unassembled material 14 to an assembly position with respect tothe first material within the tacking cell 20. This process may berepeated until all of the components of the unassembled workpiece 14 arepositioned at an appropriate assembly position within the tacking cell20.

As another example, the robotic assemblies 38 may be positioned alongthe cantilever system, as described above, within the functionaloperation area 34 to engage (e.g., grip, lift and/or transfer) theworkpiece between and within the plurality of operation cells 12.

The tacking cell 20 may perform one or more machining and/or assemblyoperations (e.g., one or more tack fastening operations) on theunassembled workpiece 14 while positioned in the assembly position. Thetacking cell 20 may utilize one or more fastening machines 78 to performinitial tack fastening of the unassembled workpiece 14. Tack fasteningmay be performed at one or more predetermined locations on theunassembled workpiece 14 while positioned in the assembly position toyield a workpiece in a partially assembled condition 30 (referred togenerally as a partially assembled workpiece 30) (FIG. 2). For example,the assembly operations performed in the tacking cell 20 (e.g., by thefastening machines 78) may include, but are not limited to, preloading(e.g., clamping) the unassembled workpiece 14, drilling fasteners holesthrough the unassembled workpiece 14, coupling fasteners (e.g., tackfasteners) to the unassembled workpiece 14, setting fasteners and thelike. As another example, the material-handling system 26 (e.g., therobotic assemblies 38) may preload (e.g., clamp) and hold theunassembled workpiece 14 while the fastening machines 78 drill fastenersholes through the unassembled workpiece 14, couple fasteners (e.g., tackfasteners) to the unassembled workpiece 14, set fasteners and the like.

Upon completion of the assembly operations performed by the tacking cell20, the robotic assemblies 38 may engage the partially assembledworkpiece 30. The gantries 36 may move to a third position (e.g.,positioning the robotic assemblies 38 within the functional operationarea 34 of the fastening cell 22), as illustrated in FIG. 8C. Therobotic assemblies 38 may transfer the partially assembled workpiece 30to an appropriate assembly position within the fastening cell 22.

The fastening cell 22 may perform one or more assembly operations on thepartially assembled workpiece 30 while positioned in the assemblyposition. The fastening cell 22 may utilize one or more fasteningmachines 78 to perform final fastening of the partially assembledworkpiece 30. Final fastening may be performed at one or morepredetermined locations on the partially assembled workpiece 30 whilepositioned in the assembly position to yield an assembled workpiece 16(FIG. 2). For example, the assembly operations performed in thefastening cell 22 (e.g., by the fastening machines 78) may include, butare not limited to, preloading (e.g., clamping) the partially assembledworkpiece 30, drilling fastener holes through the partially assembledworkpiece 30, coupling fasteners to the partially assembled workpiece30, setting fasteners, panel edge trimming, creating reference featuresfor future operations and the like. As another example, thematerial-handling system 26 (e.g., the robotic assemblies 38) maypreload (e.g., clamp) and hold the partially assembled workpiece 30while the fastening machines 78 drill fasteners holes through thepartially assembled workpiece 30, couple fasteners (e.g., tackfasteners) to the partially assembled workpiece 30, set fasteners, paneledge trimming, creating reference features for future operations and thelike.

Upon completion of the assembly operations performed by the fasteningcell 22, the robotic assemblies 38 may engage the assembled workpiece16. The gantries 36 may move to a fourth position (e.g., positioning therobotic assemblies 38 within the functional operation area 34 of theextraction cell 24), as illustrated in FIG. 8D. The robotic assemblies38 may transfer the assembled workpiece 16 to an unloading positionwithin the extraction cell 24, for example, to be unloaded to thematerial-transport system 28. The assembly manufacturing operationillustrated in FIGS. 8A, 8B, 8C and 8D may be repeated to assembleadditional assembled workpieces.

The tacking cell 20 may be configured to perform assembly operationssimilar to the fastening cell 22 (e.g., final fastening of the partiallyassembled workpiece 30) in situations where the fastening cell 22 iscausing a lag in the assembly manufacturing operation.

Additionally, one or more of the robotic assemblies 38 of one or moregantries 36 may act as a buffer station and hold the partially assembledworkpiece 30 and/or the assembled workpiece 16 while a subsequentassembly operation is being finished.

Those skilled in the art will recognize that the disclosed system 10 mayinclude other configurations of the disclosed system 10 in order tooptimize throughput of the assembly manufacturing operation. Forexample, a plurality of staging cells 18 may feed a tacking cell 20. Asanother example, a plurality of tacking cells 20 may feed a fasteningcell 22. As another example, a tacking cell 20 may feed a plurality offastening cells 22. As yet another example, a plurality of fasteningcells 22 may feed an extraction cell 24.

Referring to FIG. 6, in an example embodiment, the material-transportsystem 28 may include a cart 72 to transport the unassembled workpiece14 to, from and/or between one or more of the plurality of cells 12(e.g., to the staging cell 20 and/or from the extraction cell 24). Thecart 72 may be any carrying device suitable to hold and/or maintain theunassembled workpiece 14. The cart 72 may be customized to holddifferent types of unassembled workpiece 14. The cart 72 may be amanually guided cart (e.g., a push cart) or automatically guided cart.

In following with the aerospace example above, one configuration of thecart 72 may be configured to hold a plurality of stringers and at leastone skin in a generally horizontal orientation such that the roboticassemblies 38 may transfer the unassembled workpiece 14 from the cart 72upon entering the staging cell 18. Another configuration of the cart 72may be configured to hold one or more assembled wing planks transferredto the cart 72 by the robotic assemblies 38 in a generally verticalorientation upon entering the extraction cell 24.

One or more carts 72 may be positioned within the staging cell 18 and/orthe extraction cell 24 at any given point in the assembly manufacturingoperation.

In an example implementation of the assembly manufacturing operation, avehicle 74 may be utilized to transport the cart 72 to, from and/orbetween one or more of the plurality of cells 12. The vehicle 74 may beany mobile transport vehicle suitable to transport the cart 72. Forexample, the vehicle 74 may be a manually guided vehicle or an automatedguided vehicle. In one example, the cart 72 may include a plurality ofwheels and the vehicle 74 may drive (e.g., steer) the cart 72. Inanother example, the cart 72 may be carried by the vehicle 74. As aspecific, non-limiting example, the vehicle 74 may be an omniMove mobileplatform commercially available from KUKA Robotics Corporation ofGersthofen, Germany.

Referring to FIG. 5, the staging cell 18 and/or the extraction cell 24may include one or more positioning systems 76. The positioning system76 may define the predetermined position of the cart 72 and/or thevehicle 74 relative to the staging cell 18 such that the unassembledworkpiece 14 are properly positioned for transfer from the cart 72 bythe robotic assemblies 38. The positioning system 76 may also define thepredetermined position of the cart 72 and/or the vehicle 74 relative tothe extraction cell 24 such that the cart 72 is properly positioned fortransfer of the assembled workpiece 16 from the extraction cell 24 bythe robotic assemblies 38.

The positioning systems 76 may be any system suitable to properly andrepeatably position the cart 72 and/or the vehicle 74 relative to one ormore of the plurality of cells 12. The positioning system 76 may beconfigured to manual positioning of the cart 72 and/or the vehicle 74 orautomatic positioning of the cart 72 and/or the vehicle 74. For example,the positioning systems 76 may include, but is not limited to, cup andcone locators, electronic positioning systems, physical stops and thelike.

Those skilled in the art will recognize that the manner in which theunassembled workpiece 14 are loaded into the tacking cell 20 and/or theassembled workpiece 16 is unloaded from the fastening cell 22 maydetermine the need for the staging cell 18 and/or the extraction cell24, respectively. For example, the unassembled workpiece 14 may bemanually loaded into the tacking cell 20 and/or the assembled workpiece16 may be manually unloaded from the fastening cell 22. As anotherexample, the material-handling system 26 may be configured such that thetacking cell 20 transfers the unassembled workpiece 14 directly from thematerial-transport system 28 and/or the fastening cell 22 may beconfigured to transfer the assembled workpiece 16 directly to thematerial-transport system 28.

Referring to FIG. 5, the tacking cell 20 and the fastening cell 22 mayinclude at least one fastening machine 78 and at least one toolingfixture 80. The tooling fixture 80 of the tacking cell 20 may beconfigured to support the unassembled workpiece 14 in the assemblyposition as placed by the robotic assemblies 38. The fastening machine78 of the tacking cell 20 may be configured to prepare the unassembledworkpiece 14 for tack fastening and install tack fasteners to theunassembled workpiece 14. The tooling fixture 80 of the fastening cell22 may be configured to support the partially assembled workpiece 30(FIG. 2) in the assembly position as placed by the robotic assemblies38. The fastening machine 78 of the fastening cell 22 may be configuredprepare the partially assembled workpiece 30 for final fastening andinstall final fasteners to the partially assembled workpiece 30.

Referring to FIG. 9, in an example embodiment, the fastening machine 78may include a robot 82. The robot 82 may include a C-shaped frame 86having a throat 84. An end effector 88 may be coupled to the robot 82about an opening of the throat 84. The end effector 88 may include oneor more machining and assembly devices 114 for performing one or moremachining and/or assembly operations on a workpiece 96 (FIG. 11). Asused herein, a workpiece 96 may include the unassembled workpiece 14when used in relation to the tacking cell 20 or the partially assembledworkpiece 30 when used in relation to the fastening cell 22 (FIG. 2).For example, the machining and/or assembly operations performed by theend effector 88 may include, but are not limited to, applying a preload,locating fastener locations, drilling fastener holes, aligning fastenerholes, installing fasteners, setting fasteners, tightening fasteners,imaging, testing, inspecting and the like.

As a general, non-limiting example, the fastening method employed by theend effector 88 may include, but is not limited to, installing rivets,installing collars, installing clamps, installing bulk fasteners (e.g.,nut and bolts), welding and the like. As a specific, non-limitingexample, the tack fasteners and the final fasteners may be rivets. Themachining and assembly device 114 may be configured to drill holes ofvarious sizes to receive a range of different sizes of rivets, installappropriately sized rivets in associated holes and set the rivets (e.g.,with up to 50,000 lbs. of force) to tack fasten the unassembledworkpiece 14 together (e.g., when used in the tacking cell 20) and finalfasten the partially assembled workpiece 30 together (e.g., when used inthe fastening cell 22). In following with the aerospace example above, aplurality of robots 82 of the tacking cell 20 may install rivets to tackfasten the stringers to the skin section at approximately every 52inches along the length of the plank. A plurality of robots 82 of thefastening cell 22 may install rivets to final fasten the stringers tothe skin section at predetermined locations along the length of the wingplank.

The robot 82 may be horizontally mounted, for example, to a machinefloor or ceiling or vertically mounted, for example, to a wall. In anexample construction, the frame 86 may be coupled to a base 90. Aplurality of actuators 92 may be connected between connection locationson the base 90 and connection locations on the frame 86 to position theframe 86 with respect to the base 90.

In an example construction, the base 90 may include at least one rail100 and/or at least one rail 101. The base 90 may translate (e.g.,linearly) along rail 100 and/or rail 101 to position the robot 82relative to the workpiece (e.g., the unassembled workpiece 14 in thetacking cell 20 or the partially assembled workpiece 30 in the fasteningcell 22). The base 90 may be driven upon rail 100 and/or rail 101 by anysuitable driving system (not shown) including, but not limited to, amechanical driving system, an electromechanical driving system, ahydraulic driving system, a pneumatic driving system or the like. In aspecific, non-limiting example, the base 90 may be driven by and/or therelative position of the base with respect to the rails 100 may becontrolled by one or more servomechanisms.

In another example construction, the fastening machine 78 may includeone or more wheel assemblies (not shown) to position the robot 82relative to the workpiece (e.g., the unassembled workpiece 14 in thetacking cell 20 or the partially assembled workpiece 30 in the fasteningcell 22). For example, the base 90 may include wheel assemblies or thebase 90 may be mounted to a wheeled cart or other mobile platform. Thefastening machine 78 may be manually moved (e.g., wheeled) into positionor may be automatically moved (e.g., driven) into position.

The actuators 92 may provide for movement of the frame 86 relative tothe base 90 and a range of motion along length of the workpiece 96. Theactuators 92 may be any device suitable to position the frame 86 in anyof a plurality of discrete positions. For example, the actuators 92 maybe hydraulic or pneumatic linear stroke actuators. In an exampleconstruction, two actuators 92 may be connected to opposing sides of theframe 86 proximate a front end, two actuators 92 may be connected toopposing sides of the frame 86 proximate a middle location of the frame86 and two actuators may be connected proximate to a rear side of theframe 86. Each actuator 92 may be connected at each end by a freelymovable joint 94 such that linear actuation of one or more actuators 92may position the frame 86 (e.g., the location and angle of the throat 84and the end effector 88) relative to a work surface 98 of the workpiece96.

The actuators 92 may be configured to move and/or position the frame 86(e.g., the throat 84 and the end effector 88) at any location, forexample, in the direction of arrow 102 (e.g., along the X-axis), arrow104 (e.g., along the Y-axis) and/or arrow 106 (e.g., along the Z-axis).The actuators 92 may be configured to rotate and/or position the frame86 at any location, for example, in the direction of arrow 108 (e.g.,about the X-axis), arrow 110 (e.g., about the Y-axis) and/or arrow 112(e.g., about the Z-axis). In a specific, non-limiting example, theactuators 92 may be driven by and/or the relative position of the frame86 with respect to each of the base 90 may be controlled by one or moreservomechanisms.

Thus, the actuators 92 may provide the frame 86 with of freedom ofmovement along six axes (e.g., along the X-, Y- and/or Z-axis and aboutthe X-, Y- and/or Z-axis) and the base 90 may provide the robot 82 withfreedom of movement (e.g., linear movement) along a seventh axis (e.g.,along the Y-axis) and/or an eighth axis (e.g., along the X-axis), forexample, upon the rails 100, 101 or the wheel assemblies.

The end effector 88 may include an upper portion 88 a and an opposedlower portion 88 b. The upper portion 88 a and the lower portion 88 b ofthe end effector 88 may each be movable about the frame 86 (e.g.,linearly) in order to apply a preload to (e.g., clamp) the work surfaces98 of the workpiece 96 (FIG. 11) prior to performing a machining and/orassembly operation. For example, the upper portion 88 a and the lowerportion 88 b of the end effector 88 may be configured to apply at least1,000 lbs. of clamp force on the workpiece 96. The upper portion 88 aand the lower portion 88 b of the end effector 88 may be configured toapply an equal force to each side (e.g., opposed work surfaces 98) ofthe workpiece 96 such that the forces transferred to the base 90 aresubstantially limited or eliminated.

The throat 84 may be suitably sized to at least partially receive theworkpiece 96. The throat 84 may include a throat depth D. The throatdepth D may be of a depth sufficient to position the end effector 88 atany location over half the width of the largest applicable workpiece 96.

Referring to FIGS. 10 and 11, the tacking cell 20 and the fastening cell22 may each include a plurality of fastening machines 78 and a pluralityof tooling fixtures 80. For example, a plurality of fastening machines78 may extend longitudinally along the length of the tacking cell 20 andthe fastening cell 22, as illustrated in FIG. 10. The plurality offastening machines 78 may be positioned on both sides of the tackingcell 20 and the fastening cell 22 (e.g., laterally opposed), asillustrated in FIG. 11. The plurality of laterally opposed fasteningmachine 78 may be offset (e.g., staggered), as illustrated in FIG. 10.

The plurality of tooling fixtures 80 may include any fixture suitable tosupport and/or hold the workpiece 96 (FIG. 11) in a substantiallyhorizontal orientation such that the fastening machines 78 may performone or more machining and/or assembly operation on the workpiece 96.While the workpiece 96 is illustrated as having substantially planarwork surfaces 98, the fastening machines 78 may perform machining and/orassembly operations on workpieces 96 having non-planar, angled orcontoured work surfaces 98. The actuators 92 may position the frame 86such that the throat 84 (FIG. 9) may receive the workpiece 96 and theend effector 88 (e.g., the upper portion 88 a and the lower portion 88b) (FIG. 9) may engage the work surfaces 98 at a substantiallyperpendicular working angle.

The plurality of tooling fixtures 80 may extend longitudinally along thelength of the tacking cell 20 and the fastening cell 22, as illustratedin FIG. 10. The plurality of tooling fixtures 80 may be positionedbetween laterally opposed fastening machines 78, as illustrated in FIG.11. The vertical position of each tooling fixture 80 relative to theworkpiece 96 may be adjustable in order for one or more of the toolingfixtures 80 to move out of the way of one or more fastening machines 78.The horizontal position of each tooling fixture 80 relative to thefastening machines 78 (e.g., an adjacent fastening machine 78) may beadjustable in order to move out of the way of one or more fasteningmachines 78 and/or to minimize unsupported spans along the workpiece(e.g., the unassembled workpiece 14 in the tacking cell 20 or thepartially assembled workpiece 30 in the fastening cell 22).

In an example construction, each tooling fixture 80 may include avertically extendable and retractable stem 116. As one example, thetooling fixture retracts to provide access to the workpiece 96 by thefastening machine 78. As another example, the stem 116 may include twoor more sections 118 that may be raised to support the workpiece 96and/or lowered to allow the fastening machine 78 to access the workpiece96. Each tooling fixture 80 may include a vacuum cup 120 at an endthereof to engage the workpiece 96. For example and as illustrated inFIG. 11, as the actuators 92 move and positioned the frame 86 of therobot 82 in position to receive the workpiece 96 within the throat 84and between the end effector 88, one or more of the tooling fixtures 80positioned in front of the fastening machine 78 may lower.

In following with the aerospace example above, in an example assemblymanufacturing operation, the skin section may be positioned on theplurality of tooling fixtures 80 in the tacking cell 20 by the roboticassemblies 38. The skin section may be oriented such that the outer moldline (e.g., the exterior surface of the wing assembly) is in contactwith the vacuum cups 120 and the inner mold line (e.g., the interiorsurface of the wing assembly) is in position for placement of theplurality of stringers by the robotic assemblies 38.

Referring to FIG. 5, in an example embodiment, the material-transportsystem 28, the material-handling system 26 and the plurality ofoperation cells 12 may be programmed to interact and perform theassembly machining operation automatically. The fastening machines 78and the plurality of tooling fixtures 80 (e.g., of both the tacking cell20 and the fastening cell 22) may operate synchronously with each otherto perform the assembly machining operation automatically.

In an example implementation, the disclosed system 10 (e.g., thematerial-handling system 26, the tacking cell 20 and fastening cell 22)may automatically position of the workpiece at appropriate positionsand/or locations between and within a particular operation cell 12(e.g., the unassembled workpiece 14 in the tacking cell 20 or thepartially assembled workpiece 30 in the fastening cell 22). As anexample, the machine accuracy of the material-handling system 26 (e.g.,the gantry 36 and the robotic assembly 38), the tacking cell 29 (e.g.,the fastening machines 78 and the tooling fixtures 80) and the fasteningcell 22 (e.g., the fastening machines 78 and tooling fixtures 80) may besufficient to repeatably position the workpiece (e.g., the unassembledworkpiece 14 in the tacking cell 20 or the partially assembled workpiece30 in the fastening cell 22) such that no separate indexing or positionverification may be needed.

In another example implementation, the disclosed system 10 (e.g., thematerial-handling system 26, the tacking cell 20 and fastening cell 22)may index and/or verify the position of the workpiece. As an example,the machine accuracy of the material-handling system 26 (e.g., thegantry 36 and the robotic assembly 38), the tacking cell 29 (e.g., thefastening machines 78 and the tooling fixtures 80) and the fasteningcell 22 (e.g., the fastening machines 78 and tooling fixtures 80) mayreceive information and/or feedback from the metrology system 124. Forexample, the metrology system 124 may measure the position of theworkpiece (e.g., the unassembled workpiece 14 on the material-transportsystem 28 in the staging cell 18, the unassembled workpiece 14 in thetacking cell 20, or the partially assembled workpiece 30 in thefastening cell 22) and/or the fastening machines 78 (e.g., of thetacking cell 20 and the fastening cell 22). The information and/orfeedback may drive the components of the system 10 (e.g., the gantry 36,the robotic assembly 38, the fastening machines 78 and/or the toolingfixtures 80) to correct index positions.

As another example, the tacking cell 20 and/or fastening cell 22 mayinclude sensors and/or machine vision systems (not shown) that detectcritical features (e.g., existing pilot holes or edges) of the workpiece(e.g., the unassembled workpiece 14 in the tacking cell 20 or thepartially assembled workpiece 30 in the fastening cell 22) that allowsthe components of the system 10 (e.g., the gantry 36, the roboticassembly 38, the fastening machines 78 and/or the tooling fixtures 80)to align correctly to the workpiece. As yet another example, thecomponents of the system 10 (e.g., the gantry 36, the robotic assembly38, the fastening machines 78 and/or the tooling fixtures 80) may bedriven (e.g., automatically) to an accurate location and physically actas the index for the workpiece (e.g., the unassembled workpiece 14 inthe tacking cell 20 or the partially assembled workpiece 30 in thefastening cell 22).

The disclosed system 10 may include at least one controller 122. Thecontroller 122 may be associated with at least one of thematerial-handling system 26 (e.g., the gantry 36, the robot carriage 40,the robotic arm 42 and/or the end effector 44), the tacking cell 20(e.g., the plurality of fastening machines 78 and/or the plurality oftooling fixtures 80), the fastening cell 22 (e.g., the plurality offastening machines 78 and/or the plurality of tooling fixtures 80)and/or the material-transport system 28 (e.g., the vehicle 74).

The controller 122 may include any repeatable programming system, forexample, to drive and position (1) the material-transport system 28 topredetermined positions with respect to the staging cell 18 and/or theextraction cell 24, (2) the material-handling system 26 (e.g., thegantries 36 and the robotic assemblies 38) to predetermined positions totransfer the unassembled workpiece 14 from the material-transport system28 to the tacking cell 20, transfer the partially assembled workpiece 30from the tacking cell 20 to the fastening cell 22, transfer theassembled workpiece 16 from the fastening cell 22 to the extraction cell24 and transfer the assembled workpiece 16 from the extraction cell 24to the material-transport system 28, (3) the fastening machines 78 topredetermined machining and/or assembly locations relative to theunassembled workpiece 14 (when in the assembly position) in the tackingcell 20, (4) the fastening machines 78 to predetermined machining and/orassembly locations relative to the partially assembled workpiece 30(when in the assembly position) in the fastening cell 22 and (5) theplurality of tooling fixtures 80 to predetermined extended and/orretracted positions relative to the location of the fastening machines78 (e.g., in both the tacking cell 20 and the fastening cell 22).

The controller 122 may be pre-programmed via a desktop computer, laptopcomputer, automation controller, industrial network control system, andthe like. For example, the material-handling system 26 and the fasteningmachines 78 may include programmable industrial robots (e.g., therobotic assembly 38 and the robot 82) capable of learning (e.g., viaprogramming and iterative instruction) positional data and iterativeprocedures. Metrology, navigation and/or factory-level control softwaremay be implemented by the controller 122 and used coordinate themultiple automated and autonomous systems working in close proximitywith residual manual operations. Additionally, the metrology system 124may be used for locating, indexing, and quality-control functions.

Referring to FIG. 12, also disclosed is one embodiment of a method,generally designated 150, for assembly manufacturing. The method 150 maybegin with the step of transporting, by a material-transport system, anunassembled workpiece to a predetermined position within a staging cell,as shown at block 152.

As shown at block 154, the unassembled workpiece may be transferred, bya material-handling system, from the material-transport system to atacking cell.

As shown at block 156, the unassembled workpiece may be positioned, bythe material-handling system, in an assembly position within the tackingcell.

As shown at block 158, at least one tack fastening operation may beperformed, by a first plurality of fastening machines, on theunassembled workpiece to form a partially assembled workpiece. The tackfastening operation may include, but is not limited to, holding theunassembled workpiece, applying a preload to the unassembled workpiece,locating at least one fastening position on the unassembled workpieceand installing at least one tack fastener to the unassembled workpiece.

As shown at block 160, the partially assembled workpiece may betransferred, by the material-handling system, from the tacking cell to afastening cell.

As shown at block 162, the partially assembled workpiece may bepositioned, by the material-handling system, in an assembly positionwithin the fastening cell.

As shown at block 164, at least one final fastening operation may beperformed, by a second plurality of fastening machines, on the partiallyassembled workpiece to form an assembled workpiece. The final fasteningoperation may include, but is not limited to, holding the partiallyassembled workpiece, applying a preload to the partially assembledworkpiece, locating at least one fastening position on the partiallyassembled workpiece and installing at least one final fastener to thepartially assembled workpiece.

As shown at block 166, the assembled workpiece may be transferred, bythe material-handling system, from the fastening cell to an extractioncell.

As shown at block 168, the material-transport system may be positionedat a predetermined location within the extraction cell.

As shown at block 170, the assembled workpiece may be transferred, bythe material-handling system, from the extraction cell to thematerial-transport system.

Accordingly, the disclosure system and method includes ahigh-throughput, workpiece assembly system (e.g., large panel fasteningsystem) with multiple operational cells for automatic (e.g., robotic)drilling, tacking and fastening. The disclosed system and method mayinclude an array of automated technologies to reduce labor and toolingcosts, as well as increase throughput and free space on a factory floor.

Examples of the disclosure may be described in the context of anaircraft manufacturing and service method 200, as shown in FIG. 13, andan aircraft 202, as shown in FIG. 14. During pre-production, theaircraft manufacturing and service method 200 may include specificationand design 204 of the aircraft 202 and material procurement 206. Duringproduction, component/subassembly manufacturing 208 and systemintegration 210 of the aircraft 202 takes place. Thereafter, theaircraft 202 may go through certification and delivery 212 in order tobe placed in service 214. While in service by a customer, the aircraft202 is scheduled for routine maintenance and service 216, which may alsoinclude modification, reconfiguration, refurbishment and the like.

Each of the processes of method 200 may be performed or carried out by asystem integrator, a third party, and/or an operator (e.g., a customer).For the purposes of this description, a system integrator may includewithout limitation any number of aircraft manufacturers and major-systemsubcontractors; a third party may include without limitation any numberof venders, subcontractors, and suppliers; and an operator may be anairline, leasing company, military entity, service organization, and soon.

As shown in FIG. 14, the aircraft 202 produced by example method 200 mayinclude an airframe 218 with a plurality of systems 220 and an interior222. Examples of the plurality of systems 220 may include one or more ofa propulsion system 224, an electrical system 226, a hydraulic system228, and an environmental system 230. Any number of other systems may beincluded.

Apparatus and methods embodied herein may be employed during any one ormore of the stages of the production and service method 200. Forexample, components or subassemblies corresponding tocomponent/subassembly manufacturing 208, system integration 210, and ormaintenance and service 216 may be fabricated or manufactured using thedisclosed system 10 and method 150. Also, one or more apparatusexamples, method examples, or a combination thereof may be utilizedduring component/subassembly manufacturing 208 and/or system integration210, for example, by substantially expediting assembly of or reducingthe cost of an aircraft 202, such as the airframe 218. Similarly, one ormore of system examples, method examples, or a combination thereof maybe utilized while the aircraft 202 is in service, for example andwithout limitation, to maintenance and service 216.

The disclosed system and method are described in the context of anaircraft; however, one of ordinary skill in the art will readilyrecognize the disclosed service system and may be utilized for a varietyof different components for a variety of different types of vehicles.For example, implementations of the embodiments described herein may beimplemented in any type of vehicle including, e.g., helicopters,passenger ships, automobiles and the like.

Although various embodiments of the disclosed system and method havebeen shown and described, modifications may occur to those skilled inthe art upon reading the specification. The present application includessuch modifications and is limited only by the scope of the claims.

What is claimed is:
 1. A method for assembly manufacturing comprising:positioning a first workpiece-component and a second workpiece-componentin a staging position within a first one of a plurality of operationalcells, wherein said plurality of operational cells is arrangedsequentially and is linked together by an overhead material-handlingsystem that is shared by each one of said plurality of operationalcells; moving said first workpiece-component from said first one of saidplurality of operational cells to a first assembly position in a secondone of said plurality of operational cells using said overheadmaterial-handling system; moving said second workpiece-component fromsaid first one of said plurality of operational cells to a secondassembly position relative to said first workpiece-component using saidoverhead material-handling system; holding said secondworkpiece-component in said second assembly position using said overheadmaterial-handling system; positioning a first fastening machine, locatedwithin said second one of said plurality of operational cells, relativeto said first workpiece-component and said second workpiece-component;performing a first fastening operation to tack said firstworkpiece-component and said second workpiece-component together usingsaid first fastening machine; moving said first workpiece-component andsaid second workpiece-component from said second one of said pluralityof operational cells to a third assembly position in a third one of saidplurality of operational cells using said overhead material-handlingsystem; positioning a second fastening machine, located within saidthird one of said plurality of operational cells, relative to said firstworkpiece-component and said second workpiece-component; and performinga second fastening operation to fasten said first workpiece-componentand said second workpiece-component together using said second fasteningmachine.
 2. The method of claim 1 wherein: said first fastening machineand said second fastening machine comprise: a frame comprising a throat;an assembly end effector coupled to said frame about said throat; and aplurality of pairs of linear actuators coupled to three positions onsaid frame to position said frame with six degrees of freedom;positioning said first fastening machine comprises selectively movingsaid frame of said first fastening machine about at least one of saidsix degrees of freedom using said plurality of pairs of linear actuatorsof said first fastening machine such that a portion of said firstworkpiece-component and a portion of said second workpiece-component arelocated within said throat of said first fastening machine and saidassembly end effector of said first fastening machine is positioned forsaid first fastening operation; and positioning said second fasteningmachine comprises selectively moving said frame of said second fasteningmachine about at least one of said six degrees of freedom using saidplurality of pairs of linear actuators of said second fastening machinesuch that a portion of said first workpiece-component and a portion ofsaid second workpiece-component are located within said throat of saidsecond fastening machine and said assembly end effector of said secondfastening machine is positioned for said second fastening operation. 3.The method of claim 2 wherein a first pair of said plurality of pairs oflinear actuators is coupled to said frame proximate to a front end ofsaid frame.
 4. The method of claim 3 wherein a second pair of saidplurality of pairs of linear actuators is coupled to said frameproximate to a middle of said frame.
 5. The method of claim 4 wherein athird pair of said plurality of pairs of linear actuators is coupled tosaid frame proximate to a rear end of said frame.
 6. The method of claim2 further comprising: supporting said first workpiece-component in saidfirst assembly position using a first plurality of retractable toolingfixtures located within said second one of said plurality of operationalcells; and retracting at least one of said first plurality ofretractable tooling fixtures to accommodate said frame of said firstfastening machine in response to moving said frame of said firstfastening machine.
 7. The method of claim 6 wherein: supporting saidfirst workpiece-component in said first assembly position using saidfirst plurality of retractable tooling fixtures comprises coupling avacuum cup of each one of the said first plurality of retractabletooling fixtures to said first workpiece-component; and retracting saidat least one of said first plurality of retractable tooling fixturescomprises releasing said vacuum cup of said at least one of said firstplurality of retractable tooling fixtures and retracting a multi-sectionstem of said at least one of said first plurality of retractable toolingfixtures relative to said first workpiece-component.
 8. The method ofclaim 2 further comprising: supporting said first workpiece-componentand said second workpiece-component in said second assembly positionusing a second plurality of retractable tooling fixtures located withinsaid third one of said plurality of operational cells; and retracting atleast one of said second plurality of retractable tooling fixtures toaccommodate said frame of said second fastening machine in response tomoving said frame of said second fastening machine.
 9. The method ofclaim 1 wherein said first fastening operation comprises: applying apreload to said first workpiece-component and said secondworkpiece-component; locating a first fastening position; and installinga tack fastener to said first workpiece-component and said secondworkpiece-component at said first fastening position.
 10. The method ofclaim 1 further comprising: moving said first workpiece-component andsaid second workpiece-component to said staging position within saidfirst one of said plurality of operational cells using amaterial-transport system.
 11. The method of claim 10 wherein saidmaterial-transport system comprises: a vehicle; and a cart coupled tosaid vehicle and configured to hold said workpiece.
 12. The method ofclaim 11 wherein said vehicle is an automated guided vehicle.
 13. Themethod of claim 12 further comprising automatically moving said vehicleto a predetermined position relative to said first one of said pluralityof operational cells using a positioning system.
 14. The method of claim1 wherein: said overhead material-handling system comprises: a transferrail positioned above said plurality of operational cells; a robotcarriage coupled to said transfer rail; a robotic arm coupled to saidrobot carriage; and a gripping end effector coupled to said robotic arm;and moving said first workpiece-component to said first assemblyposition, moving said second workpiece-component to second assemblyposition, holding said second workpiece-component in said secondassembly position, and moving said first workpiece-component and saidsecond workpiece-component to said third assembly position comprisesmoving said robot carriage along said transfer rail and articulatingsaid robotic arm to appropriately position said gripping end effector.15. The method of claim 1 further comprising, with said firstworkpiece-component in said first assembly position and said secondworkpiece-component in said second assembly position: positioning athird fastening machine, located within said second one of saidplurality of operational cells opposite to said first fastening machine,relative to said first workpiece-component and said secondworkpiece-component; and performing said first fastening operation totack said first workpiece-component and said second workpiece-componenttogether using said third fastening machine.
 16. The method of claim 1further comprising, with said first workpiece-component and said secondworkpiece-component in said third assembly position: positioning afourth fastening machine, located within said third one of saidplurality of operational cells opposite to said second fasteningmachine, relative to said first workpiece-component and said secondworkpiece-component; and performing said second fastening operation tofasten said first workpiece-component and said secondworkpiece-component together using said fourth fastening machine. 17.The method of claim 1 wherein said second fastening operation comprises:applying a preload to said first workpiece-component and said secondworkpiece-component; locating a second fastening position; andinstalling a final fastener to said first workpiece-component and saidsecond workpiece-component at said second fastening position.
 18. Themethod of claim 1 further comprising indexing said secondworkpiece-component at said second assembly position relative to saidfirst workpiece-component using a metrology system.
 19. The method ofclaim 1 further comprising moving said first workpiece-component andsaid second workpiece-component from said third one of said plurality ofoperational cells to an extraction position in a fourth one of saidplurality of operational cells using the overhead material-handlingsystem.
 20. The method of claim 1 wherein: said firstworkpiece-component comprises a skin panel of a wing; and said secondworkpiece-component comprises a plurality of stringers of said wing;moving said second workpiece-component comprises successively movingeach one of said plurality of stringers to said second assembly positionusing said overhead material-handling system; and holding said secondworkpiece-component comprises holding each one of said stringers in saidsecond assembly position while performing said first fastening operationto tack each one of said stringers and said skin panel together usingsaid first fastening machine.